The prime minister made the uncharacteristically blunt comments during an appearance in Regina with Saskatchewan Premier Brad Wall.

Harper said the plan would be worse than the old national energy program introduced under the government of Pierre Trudeau in 1980, which still sparks fury among many Western Canadians to this day.

"It is like the national energy program in the sense that the national energy program was designed to screw the West and really damage the energy sector — and this will do those things," Harper said. "This is different in that this will actually screw everybody across the country.

"That is really what the Liberal Party is proposing and I hope that it won't fool Canadians."

Western resentment over NEP still lingers

Dion's carbon "green shift" plan, revealed on Thursday in Ottawa, would levy $15.4 billion in new taxes on Canadian industries that produce high carbon emissions, and use the proceeds to cut taxes for people facing higher energy costs and other rising prices.

It would initially peg the price of greenhouse gas emissions at $10 per tonne, rising to $40 per tonne in the fourth year.

Harper, who has previously called Dion's plan "insane," said the policy is not only bad for Western Canada, but "will recklessly harm the economy and the economic position of every Canadian family."

Created in the wake of the energy crises of the 1970s, the NEP had three main objectives: to boost Canadian ownership in the oil industry, to make the country a self-sufficient oil producer and to increase the federal share of energy revenue.

As part of the program, Trudeau launched a tax to fund the federal government's gas company, Petro-Canada, and gave grants to Canadian-owned oil companies.

Western provinces, particularly Alberta, were furious about the NEP. Many Albertans saw it as a federal intrusion on provincial matters and believed the program was designed to make the province less wealthy.

Plan would take Sask. back to 'have-not' status: Wall

Standing next to Harper, Wall said the carbon tax could hurt the province's economic development. Wall, who leads the Saskatchewan Party, suggested such a plan could potentially force Saskatchewan back to "have-not" status once again.

"We're going to see wealth and opportunity and growth transferred under this kind of a fiscal tool from our province to elsewhere," Wall said. "We will see the effective knee-capping of our economy.

"It's important for us to stand up and say, 'Look, this is going to come at a great cost to a part of the national economy that's working right now and working very well.'"